Every year there are new smartphones, more and more powerful and voracious. But mobile batteries are not developing as fast as we would like. Therefore, you may need a power bank - a compact external battery that will recharge your phone in the absence of sockets.

Portable power supplies, unlike the same smartphones and other types of advanced technology, can not boast of a special variety. And this is quite logical. But there are some things you need to know about them.

How to choose a good power bank?


Capacity

The most important parameter of an external battery is its capacity, which the manufacturer usually indicates in milliampere-hours (mAh). Roughly speaking, this is the amount of energy that a power bank can store (but not transmit).

Please note: due to the fundamental laws of physics, no external battery can transfer 100% of the stored energy and no smartphone can fully absorb the energy received. Part of the resource is always lost when the voltage is converted, and a certain amount goes into heat.

Connectors and cables

Many external batteries, especially budget models, are sold without wires. It is assumed that you will use the USB cable that comes with your smartphone to connect. In this case, make sure that the end of this wire (most often a USB-A or USB-C port) matches the type of output connector on the power bank.

Supportoffast charging

Let's say you found an external battery with a suitable current output, but the included plug still charges the smartphone faster. What's the matter? Most likely, your smartphone supports some kind of accelerated charging technology like Quick Charge 3.0, Quick Charge 4.0, or a variant with its own name from a specific manufacturer (for example, mCharge from Meizu). Look for a power bank that is friendly with the fast charging technology that is used in your smartphone.

TOP-5 power banks with 20000 mAh of 2021


These models are characterized by long-term operation and quality of filling with energy, high efficiency, and a large number of recharge cycles.

1. ROMOSS Sense6PS+ 20000mAh

ROMOSS Sense6PS+ Power Bank

Romoss external battery with a capacity of 20,000 mAh, with two-way fast charging. One charge lasts for 5 days.

iPhone 8 can be charged up to 9.6 times, iPhone 11 can be charged 1 time a day and use the battery for more than a week, Charges iPhone 11 by 50% in half an hour, Xiaomi 9 can be charged in an hour, iPhone 8 about 8 times, Huawei P10 about 4.3 times, Galaxy S8 about 4 times, iPad mini about 2 times, iPhone 11 about 6 times, oppo R11s about 5 times.

Supports the most advanced protocols such as QC3. 0/2. 0, MTK PE and Huawei FCP.

After much testing, the battery can charge the Xiaomi 9 to 90% in an hour using the original Xiaomi cable.

Automatically adjusts the output power to provide optimal charging current, keeping your devices from overcharging, over-current, over-voltage, and short-circuiting.


Pros:

Two-way Fast Charging;

Approximately 5 days on one charge;

Supports iOS and Android devices.


Cons:

Weight is almost 500g.

2. Xiaomi Redmi Power Bank 20000 mAh

Xiaomi Redmi Power Bank 20000 mAh

Compact Power Bank Xiaomi Redmi 20000mAh large capacity for travel, travel and charge a large amount of equipment.

Charge the right number of devices at the same time. 2 USB-A, Micro-USB, Type-C connectors. Charge smartphones, power-intensive devices, and low-current watches and wristbands.

Xiaomi Redmi batteries are approved by airlines as safe. Safely take the battery with you in your hand luggage. Built-in protection against short circuits, and surges in the network, protection against over-discharge and overheating.

Only the battery is included, the manufacturer did not put the cable.


Pros:

Protection against short circuits, overheating and etc;

Size. Very compact power bank;

Fast Charging.


Cons:

Comes without a cable.

3. ROMOSS LT20 Power Bank 20000mAh

ROMOSS LT20 Power Bank

A smartphone with a battery capacity of 3 200 mAh battery is capable of charging about 5-6 times.

Self-charging time, according to the seller's description: ~ 13 hours (using a 2.1 A adapter).

Connectors: Apple, 2xUSB(1 Lightning-1A, 2 Lightning-2.1 A), Micro-USB and Type-C fast charging connector.

The display shows the percentage of charge of the device, quite informative and very convenient.


Pros:

Display;

For iOS and android devices.


Cons:

Charging time.

4. KUULAA Power Bank 20000mAh QC PD 3.0

KUULAA Power Bank 20000mAh

The portable battery supports charging multiple devices at once, thanks to it, an unexpectedly dead phone will never catch you by surprise. Plus, there is the support of FAST CHARGING

There is a display that shows the charging level and protocol.

At the end there are all the connectors that are also signed:

• Lightning;
•USB Type-C;
• Micro-USB;
• Usb 1;
• Usb 2.

On the opposite side, the technical specifications are indicated. From them, we can see that the model is called KL-YD08 and has a capacity of 20000mAh, 74Wh, which is 2Wh more than the Essager 20000mah. And in addition, it's supporting charging via Type-C5V 3A. All ports simultaneously produce a total of a maximum of 3A at 5V.


Pros:

Five ports;

Fast Charging.


Cons:

Only 18W output.

5. TOPK Power Bank 20000mAh

TOPK Power Bank 20000mAh

The model is made in a pleasant design with a combined finish of rough and soft to the touch plastic. On one of the ends of the brick with rounded edges, there are two standard USB-A ports, as well as USB-C and microUSB. On the front panel, there are five LED indicators that display the remaining charge.

The battery capacity is 20,000 mAh, the output power is 18 W, the fast charging standards Quick Charge 3.0 and Power Delivery 3.0 are supported. The power bank itself is recharged from 0 to 100% in 6-7 hours.


Pros:

Fast Charging;

Charges in 6-7 hours.


Cons:

Only 18W output;

No display.